// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2011 Benoit Jacob <jacob.benoit.1@gmail.com>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.

#include "main.h"

template<typename MatrixType>
void
zeroReduction(const MatrixType& m)
{
	// Reductions that must hold for zero sized objects
	VERIFY(m.all());
	VERIFY(!m.any());
	VERIFY(m.prod() == 1);
	VERIFY(m.sum() == 0);
	VERIFY(m.norm() == 0);
	VERIFY(m.squaredNorm() == 0);
	VERIFY(m.count() == 0);
	VERIFY(m.allFinite());
	VERIFY(!m.hasNaN());
	VERIFY_RAISES_ASSERT(m.minCoeff());
	VERIFY_RAISES_ASSERT(m.maxCoeff());
	Index i, j;
	VERIFY_RAISES_ASSERT(m.minCoeff(&i, &j));
	VERIFY_RAISES_ASSERT(m.maxCoeff(&i, &j));
	VERIFY_RAISES_ASSERT(m.reshaped().minCoeff(&i));
	VERIFY_RAISES_ASSERT(m.reshaped().maxCoeff(&i));
}

template<typename MatrixType>
void
zeroSizedMatrix()
{
	MatrixType t1;
	typedef typename MatrixType::Scalar Scalar;

	if (MatrixType::SizeAtCompileTime == Dynamic || MatrixType::SizeAtCompileTime == 0) {
		zeroReduction(t1);
		if (MatrixType::RowsAtCompileTime == Dynamic)
			VERIFY(t1.rows() == 0);
		if (MatrixType::ColsAtCompileTime == Dynamic)
			VERIFY(t1.cols() == 0);

		if (MatrixType::RowsAtCompileTime == Dynamic && MatrixType::ColsAtCompileTime == Dynamic) {

			MatrixType t2(0, 0), t3(t1);
			VERIFY(t2.rows() == 0);
			VERIFY(t2.cols() == 0);

			zeroReduction(t2);
			VERIFY(t1 == t2);
		}
	}

	if (MatrixType::MaxColsAtCompileTime != 0 && MatrixType::MaxRowsAtCompileTime != 0) {
		Index rows = MatrixType::RowsAtCompileTime == Dynamic ? internal::random<Index>(1, 10)
															  : Index(MatrixType::RowsAtCompileTime);
		Index cols = MatrixType::ColsAtCompileTime == Dynamic ? internal::random<Index>(1, 10)
															  : Index(MatrixType::ColsAtCompileTime);
		MatrixType m(rows, cols);
		zeroReduction(m.template block<0, MatrixType::ColsAtCompileTime>(0, 0, 0, cols));
		zeroReduction(m.template block<MatrixType::RowsAtCompileTime, 0>(0, 0, rows, 0));
		zeroReduction(m.template block<0, 1>(0, 0));
		zeroReduction(m.template block<1, 0>(0, 0));
		Matrix<Scalar, Dynamic, Dynamic> prod = m.template block<MatrixType::RowsAtCompileTime, 0>(0, 0, rows, 0) *
												m.template block<0, MatrixType::ColsAtCompileTime>(0, 0, 0, cols);
		VERIFY(prod.rows() == rows && prod.cols() == cols);
		VERIFY(prod.isZero());
		prod = m.template block<1, 0>(0, 0) * m.template block<0, 1>(0, 0);
		VERIFY(prod.size() == 1);
		VERIFY(prod.isZero());
	}
}

template<typename VectorType>
void
zeroSizedVector()
{
	VectorType t1;

	if (VectorType::SizeAtCompileTime == Dynamic || VectorType::SizeAtCompileTime == 0) {
		zeroReduction(t1);
		VERIFY(t1.size() == 0);
		VectorType t2(DenseIndex(0)); // DenseIndex disambiguates with 0-the-null-pointer (error with gcc 4.4 and MSVC8)
		VERIFY(t2.size() == 0);
		zeroReduction(t2);

		VERIFY(t1 == t2);
	}
}

EIGEN_DECLARE_TEST(zerosized)
{
	zeroSizedMatrix<Matrix2d>();
	zeroSizedMatrix<Matrix3i>();
	zeroSizedMatrix<Matrix<float, 2, Dynamic>>();
	zeroSizedMatrix<MatrixXf>();
	zeroSizedMatrix<Matrix<float, 0, 0>>();
	zeroSizedMatrix<Matrix<float, Dynamic, 0, 0, 0, 0>>();
	zeroSizedMatrix<Matrix<float, 0, Dynamic, 0, 0, 0>>();
	zeroSizedMatrix<Matrix<float, Dynamic, Dynamic, 0, 0, 0>>();
	zeroSizedMatrix<Matrix<float, 0, 4>>();
	zeroSizedMatrix<Matrix<float, 4, 0>>();

	zeroSizedVector<Vector2d>();
	zeroSizedVector<Vector3i>();
	zeroSizedVector<VectorXf>();
	zeroSizedVector<Matrix<float, 0, 1>>();
	zeroSizedVector<Matrix<float, 1, 0>>();
}
